The invention concerns hair treating compositions and their methods of use. More specifically, the invention concerns compositions that when applied to hair improve properties such as its hand (feel), curl retention, color receptivity, color stability, color retention, shine, and strength and that can be used to prevent or repair damage to hair caused by hair treating processes (e.g., hair waving and coloring).
Hair treating compositions and methods for treating hair have been used for many years. Compositions used include coating compositions to hold hair in a particular manner and compositions to improve hair strength, shine, color, arrangement, or other properties or to prevent or repair damage to hair. Current popular hair treatments include permanent waving and hair coloring, both of which involve chemical treatments that tend to injure hair.
There are numerous methods and compositions for permanent waving, which involves arranging the hair in the desired configuration and then treating the hair to semi-permanently retain the arrangement. The initial step is a waving step in which the hair is "relaxed" by breaking the disulfide bonds in the keratin of the hair using a reducing agent. Compositions used to break those bonds include solutions of thioglycolic acid (at pH 8.5-9.5 if an alkaline wave or pH 6.5-6.95 if an acid wave) or a sulfite/bisulfite solution (at pH 5.5-8.5) containing alkalis such as alkali metal compounds, ammonium hydroxide, or amines (e.g., monoethanolamine) to provide the alkaline pH. After breaking the keratin's disulfide bonds, the hair is fixed in the desired arrangement using an oxidizing agent (e.g., hydrogen peroxide or sodium bromate) to reestablish disulfide bonds in the keratin.
The reduction within the hair fiber is of the amino acid cystine, which contains a centrally located disulfide bond. When this bond in a cystine molecule is cleaved using the reducing solution (usually called the "waving solution"), the cystine molecule forms two molecules of the amino acid cysteine, each having a terminal sulfhydryl group resulting from the disulfide cleavage.
If the hair is to be curled, the hair is typically rolled onto rods of various sizes, contacted with the reducing (or waving) solution, and permitted to remain in contact with the solution until the required amount of reduction has occurred. Typically, the at-least-partially-spent reducing solution or lotion is thoroughly rinsed from the hair, the hair is towel dried, and the neutralizer (oxidizing composition) is applied. The neutralizer reoxidizes the sulfhydryl groups to disulfide groups to fix the hair in the new arrangement. If curls are required, the hair is neutralized while still on the rods. Hair may also be straightened, i.e., the natural curl removed from the hair, in which case the hair is combed while in contact with the reducing solution and then combed while the neutralizer or oxidizing solution is applied. In either case (curling or straightening), the procedure is completed by rinsing the neutralizer (oxidizer) from the hair. It is usually recommended that hair not be shampooed for at least 24 hours after the permanent waving procedure to provide the tightest curl or straightest hair, as the case may be, because even after removal of the oxidizing solution from the surface of the hair, reaction within the hair (i.e., reformation of disulfide bonds) continues.
Many attempts have been made to provide waving and other treating compositions that prevent some or all of the damage to the hair before it occurs or that repair the damage after it has occurred. See, e.g., U.S. Pat. Nos. 3,266,994, 4,186,188, 4,494,557, 4,658,839, 4,793,992, 4,906,461, 5,015,470, and 5,051,252, U.K. Patent Application No. 2,153,865, and EPO Patent No. 443,356. (All of those documents as well as all others referenced and/or discussed herein are incorporated herein in their entireties for all purposes.)
Some hair treating compositions include salts (e.g., salts of polyvalent metals); see, e.g., U.S. Pat. Nos. 3,266,994 and 5,051,252 and U.K. Patent Application No. 2,153,865. Some hair treating compositions include proteins or polypeptides or amino acids (e.g., keratin, which is an important constituent of hair, nails, wool, and feathers, or low molecular weight protein fragments such as hydrolyzed protein, or amino acids such as cystine and cysteine, the first of which is a constituent of the keratin in the hair and the second of which results from the cleavage of cystine); see, e.g., U.S. Pat. Nos. 4,186,188, 4,494,557, 4,658,839, 4,793,992, and EPO 443,356. Some hair treating compositions use proteinaceous material and salt. See, e.g., U.S. Pat. No. 4,494,557, which concerns an aqueous hair conditioning composition for permanent waving that contains (a) 15.7 to 34.8% of a reconstructor solution, the preferred reconstructor solution containing hydrolyzed animal protein and keratin having 3.2% cystine, and (b) 24.1 to 41.6% magnesium sulfate. (Commercial KERAPHIX, the preferred reconstructor solution used in U.S. Pat. No. 4,494,557, is said to contain numerous ingredients, including keratin amino acids, glycerine, mineral oil, safflower oil, zinc chloride, magnesium citrate, and manganese citrate.) Some hair treating compositions include acids (e.g., mineral acids or carboxylic acids such as citric acid); see, e.g., U.S. Pat. Nos. 3,266,944, 4,793,992, 4,906,461, and 5,015,470. Some hair treating compositions use all three types of materials, namely, salts of polyvalent metals, proteins or polypeptides or amino acids, and mineral or carboxylic acids; see, e.g., U.S. Pat. Nos. 4,793,992 and 4,906,461.
Proteins said to be useful in hair treatment by their purveyor, Croda Inc., include HYDROTRITICUM 2000 (hydrolyzed whole wheat protein, which has an average molecular weight of 3,000, is available as a 20% solution, contains 1.8% cystine, contains 1.3% methionine, and is said typically to be used at a 1-5% level) and other HYDROTRITICUM preparations, HYDROSOY 2000/SF (hydrolyzed soy protein solution, which has an average molecular weight of about 4,000, is available as a 20% solution, contains 1.0% cystine, contains 1.3% methionine, and is said typically to be used at a 0.2-3% level), KERASOL (a soluble keratin preparation, which has an average molecular weight of about 125,000), CROQUAT WKP (cocodimonium hydrolyzed animal keratin, which has an average molecular weight of about 1,000, is available as a 30% solution, contains about 10.2% cystine and no methionine, and is said typically to be used at a 0.25-2% level) and other CROQUAT preparations, CROTEIN WKP (hydrolyzed wool-based protein, which has an average molecular weight of about 600, is available as a 22% solution, contains about 10.2% cystine and no methionine, and is said typically to be used at a 0.2-3% level) and other CROTEIN preparations, and CROSILKQUAT (cocodimonium silk amino acids, which has an average molecular weight of 320, is available as a 30% solution, contains 0.2% methionine, and contains 0.1% cystine). The presence of cystine in some of these materials is said by Croda to be particularly desirable because, among other reasons, the cystine can permanently bind to the hair under certain conditions and can minimize the loss of cystine from the keratin of the hair during waving.
The hydrolyzed proteins used in the formulation referenced in column 5, lines 3-22, of U.S. Pat. No. 4,793,992 are CROTEIN SPC (hydrolyzed collagen, which has an average molecular weight of 10,000, is available as a powder with an activity of 93%, contains 0.7 to 0.9% methionine, and contains no more than 0.9% cystine), CROSILK LIQUID (mixture of amino acids derived from hydrolyzed silk protein, which has an average molecular weight of 92, contains 0.2% methionine, and contains about 0.1% cystine), and AMINO GLUTEN MG (mixture of amino acids derived from maize gluten protein, which contains little or no methionine and no cystine). Those three materials are all marketed by Croda Inc. and the formulation of the patent contains 2% of each of them, for a total of 6% of the formulation. In addition, the referenced formulation of U.S. Pat. No. 4,793,992 contains 0.1% of the hydrolyzed protein that is described in U.S. Pat. No. 4,186,188, 2.5% magnesium sulfate, and 1% citric acid and it has a pH of about 5.
A hair conditioner marketed by Redkin Laboratories, Inc. under the name CAT is believed to have a pH of about 6.6 and to contain about 0.4% magnesium sulfate, more than 0.4% soy protein, less than 0.4% CROQUAT WKP, and optionally citric acid, with a total of about 3% solids.
As noted above, the typical permanent waving process requires a rinsing step between the application of the reducing solution and the application of the oxidizing (neutralizing) solution. This intermediate rinse is widely thought to be needed to remove as much of the reducing solution as possible from the hair because the pH of the reducing solution is usually higher than that of the oxidizing solution and if left on the hair in any significant amount, the reducing solution would react with a significant amount of the oxidizing (neutralizing) solution and reduce the latter's effectiveness, especially in the hair fibers into which the oxidizing solution had poorly penetrated. The failure to reform enough disulfide bonds, e.g., if the neutralizer were not sufficiently effective (as would be the case if the reducing solution left on the hair significantly reduced the efficacy of the neutralizer), is highly undesirable because the resulting hair will have poor curl and tend to be straw-like, brittle, feel rough, etc. Hence, the generally recognized need for the intermediate rinse.
On the other hand, it would be desirable to eliminate the intermediate rinse, that is, to use a "rinse-free waving process," because the rinsing step: causes loss of keratin, amino acids, and color from the hair fiber; causes physical damage to the cuticle and cortex of the hair because of the pressurized water jets typically used in hair salons during rinsing; utilizes approximately nine gallons of water with every permanent; is time-consuming, thereby reducing the number of permanent wave customers a hair salon can service per day; and causes swelling of the fiber over and above that caused by the waving lotion. The damage caused by excessive swelling is generally irreversible. (As used herein, the term "rinse-free waving process" will be used to refer to all types of waving processes, including curling and straightening processes, in which there is no intermediate rinse, that is, there is no rinse between application of the waving (reducing) solution and application of the neutralization (oxidizing) solution.)
U.K. Patent Application 2,153,865 concerns a waving process. Hair is treated with reducing solution to achieve substantially maximum cystine cleavage, blotted to remove the reactive reducing solution, contacted with a so-called protein flow solution, arranged in the desired configuration, rinsed, and contacted with an oxidizing agent to reestablish the cystine bonds. The protein flow solution is an aqueous solution containing a polyvalent metal having acceptable toxicity (for example, a magnesium or calcium salt, e.g., magnesium sulfate) in a concentration of about 1 to 10% by weight of the solution and/or a water-soluble hydroxyorganic compound containing one or more hydroxyl groups and up to about 4 carbon atoms, namely, an alcohol or polyol (for example, ethanol). The pH is desirably 2 to 10, preferably about 6 to 7, and may be adjusted using alkaline compounds such as alkaline amino acids (cystine and cysteine peptides, proteins, and amino acids are acidic and not alkaline).
A recently marketed product, PRO-IONIC QUENCH.TM. from Pro-Design International, is said to be useful in a rinse-free waving process in which two different solutions are applied to the hair after waving and blotting and before neutralization. The first solution is believed to have a pH of about 8.3, to contain a bicarbonate salt, and to have only about 5 parts per million of magnesium. The second solution is believed to have a pH of about 2.4 and to contain about 4.5% magnesium sulfate, some citric acid or sodium citrate, and some HYDROTRITICUM (which contains about 1.8% cystine and about 1.5% methionine). The product is said to improve hair strength, color retention, etc.
It is known that the best time to place hair strengthening agents into the cortex of the hair is after the waving solution has swollen the fiber, which swelling opens the cortex, and before the neutralizer deswells or shrinks the fiber. It is also known that it is desirable to protect the cuticle and cortex of the hair from the damaging effects of the neutralizer solution.
Separate and apart from waving processes, it is also desirable to impart color receptivity, color stability, color retention, good hand, softness, manageability, curl strength and retention, etc. to hair that has been or is being colored either in a coloring process or in a combined waving and coloring process. It is also desirable to impart such properties to hair that may have been damaged by waving, coloring, or other processes and/or by environmental factors (e.g., excessive sunlight).
Despite the substantial work done over the years, the need remains for a hair treating composition that when applied to hair can improve properties such as its hand (feel), curl retention, color retention, shine, strength, and the other properties mentioned herein and that can be used to prevent or repair damage to hair caused by hair treating processes (e.g., hair waving and coloring) and environmental factors.